diff options
Diffstat (limited to 'libs/utils/backup_data.cpp')
| -rw-r--r-- | libs/utils/backup_data.cpp | 228 |
1 files changed, 210 insertions, 18 deletions
diff --git a/libs/utils/backup_data.cpp b/libs/utils/backup_data.cpp index c7f1fdb..dd04449 100644 --- a/libs/utils/backup_data.cpp +++ b/libs/utils/backup_data.cpp @@ -14,12 +14,16 @@ * limitations under the License. */ +#define LOG_TAG "backup_data" + #include <utils/backup_helpers.h> #include <utils/ByteOrder.h> #include <stdio.h> #include <unistd.h> +#include <cutils/log.h> + namespace android { /* @@ -39,22 +43,6 @@ namespace android { #define ENTITY_MAGIC_V1 0x61746144 // Data (little endian) #define FOOTER_MAGIC_V1 0x746f6f46 // Foot (little endian) -typedef struct { - int type; // == APP_MAGIC_V1 - int packageLen; // length of the name of the package that follows, not including the null. -} app_header_v1; - -typedef struct { - int type; // ENTITY_MAGIC_V1 - int keyLen; // length of the key name, not including the null terminator - int dataSize; // size of the data, not including the padding -} entity_header_v1; - -typedef struct { - int type; // FOOTER_MAGIC_V1 - int entityCount; // the number of entities that were written -} app_footer_v1; - const static int ROUND_UP[4] = { 0, 3, 2, 1 }; static inline size_t @@ -102,7 +90,7 @@ BackupDataWriter::write_padding_for(int n) } status_t -BackupDataWriter::WriteAppHeader(const String8& packageName) +BackupDataWriter::WriteAppHeader(const String8& packageName, int cookie) { if (m_status != NO_ERROR) { return m_status; @@ -122,6 +110,7 @@ BackupDataWriter::WriteAppHeader(const String8& packageName) header.type = tolel(APP_MAGIC_V1); header.packageLen = tolel(nameLen); + header.cookie = cookie; amt = write(m_fd, &header, sizeof(app_header_v1)); if (amt != sizeof(app_header_v1)) { @@ -204,7 +193,7 @@ BackupDataWriter::WriteEntityData(const void* data, size_t size) } status_t -BackupDataWriter::WriteAppFooter() +BackupDataWriter::WriteAppFooter(int cookie) { if (m_status != NO_ERROR) { return m_status; @@ -222,6 +211,7 @@ BackupDataWriter::WriteAppFooter() footer.type = tolel(FOOTER_MAGIC_V1); footer.entityCount = tolel(m_entityCount); + footer.cookie = cookie; amt = write(m_fd, &footer, sizeof(app_footer_v1)); if (amt != sizeof(app_footer_v1)) { @@ -233,4 +223,206 @@ BackupDataWriter::WriteAppFooter() return NO_ERROR; } + +BackupDataReader::BackupDataReader(int fd) + :m_fd(fd), + m_status(NO_ERROR), + m_pos(0), + m_entityCount(0) +{ + memset(&m_header, 0, sizeof(m_header)); +} + +BackupDataReader::~BackupDataReader() +{ +} + +status_t +BackupDataReader::Status() +{ + return m_status; +} + +#define CHECK_SIZE(actual, expected) \ + do { \ + if ((actual) != (expected)) { \ + if ((actual) == 0) { \ + m_status = EIO; \ + } else { \ + m_status = errno; \ + } \ + return m_status; \ + } \ + } while(0) +#define SKIP_PADDING() \ + do { \ + status_t err = skip_padding(); \ + if (err != NO_ERROR) { \ + m_status = err; \ + return err; \ + } \ + } while(0) + +status_t +BackupDataReader::ReadNextHeader() +{ + if (m_status != NO_ERROR) { + return m_status; + } + + int amt; + + SKIP_PADDING(); + amt = read(m_fd, &m_header, sizeof(m_header)); + CHECK_SIZE(amt, sizeof(m_header)); + + // validate and fix up the fields. + m_header.type = fromlel(m_header.type); + switch (m_header.type) + { + case APP_MAGIC_V1: + m_header.app.packageLen = fromlel(m_header.app.packageLen); + if (m_header.app.packageLen < 0) { + LOGD("App header at %d has packageLen<0: 0x%08x\n", (int)m_pos, + (int)m_header.app.packageLen); + m_status = EINVAL; + } + m_header.app.cookie = m_header.app.cookie; + break; + case ENTITY_MAGIC_V1: + m_header.entity.keyLen = fromlel(m_header.entity.keyLen); + if (m_header.entity.keyLen <= 0) { + LOGD("Entity header at %d has keyLen<=0: 0x%08x\n", (int)m_pos, + (int)m_header.entity.keyLen); + m_status = EINVAL; + } + m_header.entity.dataSize = fromlel(m_header.entity.dataSize); + if (m_header.entity.dataSize < 0) { + LOGD("Entity header at %d has dataSize<0: 0x%08x\n", (int)m_pos, + (int)m_header.entity.dataSize); + m_status = EINVAL; + } + m_entityCount++; + break; + case FOOTER_MAGIC_V1: + m_header.footer.entityCount = fromlel(m_header.footer.entityCount); + if (m_header.footer.entityCount < 0) { + LOGD("Entity header at %d has entityCount<0: 0x%08x\n", (int)m_pos, + (int)m_header.footer.entityCount); + m_status = EINVAL; + } + m_header.footer.cookie = m_header.footer.cookie; + break; + default: + LOGD("Chunk header at %d has invalid type: 0x%08x", (int)m_pos, (int)m_header.type); + m_status = EINVAL; + } + m_pos += sizeof(m_header); + + return m_status; +} + +status_t +BackupDataReader::ReadAppHeader(String8* packageName, int* cookie) +{ + if (m_status != NO_ERROR) { + return m_status; + } + if (m_header.type != APP_MAGIC_V1) { + return EINVAL; + } + size_t size = m_header.app.packageLen; + char* buf = packageName->lockBuffer(size); + if (packageName == NULL) { + packageName->unlockBuffer(); + m_status = ENOMEM; + return m_status; + } + int amt = read(m_fd, buf, size+1); + CHECK_SIZE(amt, (int)size+1); + packageName->unlockBuffer(size); + m_pos += size+1; + *cookie = m_header.app.cookie; + return NO_ERROR; +} + +bool +BackupDataReader::HasEntities() +{ + return m_status == NO_ERROR && m_header.type == ENTITY_MAGIC_V1; +} + +status_t +BackupDataReader::ReadEntityHeader(String8* key, size_t* dataSize) +{ + if (m_status != NO_ERROR) { + return m_status; + } + if (m_header.type != ENTITY_MAGIC_V1) { + return EINVAL; + } + size_t size = m_header.app.packageLen; + char* buf = key->lockBuffer(size); + if (key == NULL) { + key->unlockBuffer(); + m_status = ENOMEM; + return m_status; + } + int amt = read(m_fd, buf, size+1); + CHECK_SIZE(amt, (int)size+1); + key->unlockBuffer(size); + m_pos += size+1; + *dataSize = m_header.entity.dataSize; + SKIP_PADDING(); + return NO_ERROR; +} + +status_t +BackupDataReader::ReadEntityData(void* data, size_t size) +{ + if (m_status != NO_ERROR) { + return m_status; + } + int amt = read(m_fd, data, size); + CHECK_SIZE(amt, (int)size); + m_pos += size; + return NO_ERROR; +} + +status_t +BackupDataReader::ReadAppFooter(int* cookie) +{ + if (m_status != NO_ERROR) { + return m_status; + } + if (m_header.type != FOOTER_MAGIC_V1) { + return EINVAL; + } + if (m_header.footer.entityCount != m_entityCount) { + LOGD("entity count mismatch actual=%d expected=%d", m_entityCount, + m_header.footer.entityCount); + m_status = EINVAL; + return m_status; + } + *cookie = m_header.footer.cookie; + return NO_ERROR; +} + +status_t +BackupDataReader::skip_padding() +{ + ssize_t amt; + ssize_t paddingSize; + + paddingSize = padding_extra(m_pos); + if (paddingSize > 0) { + uint32_t padding; + amt = read(m_fd, &padding, paddingSize); + CHECK_SIZE(amt, paddingSize); + m_pos += amt; + } + return NO_ERROR; +} + + } // namespace android |